78 Chevy Blazer axles

gmbarker78

New Member
Joined
Sep 9, 2008
Location
5671 Elk Creek/Darby Rd.
I have a question and sorry for not knowing any better. I have a chance to haul off a 78 Chevy full size 4WD Blazer. I can't identify the axles under it, for one it's sitting on the ground. Was there a basic axle set-up used for that year? Common gear ratio? The diff covers appear to have 12 bolts, and they are 6 lug axles. thanks for any help.
Gary
 
78 axles

the front should have a 10 bolt 28 spline axle and rear is a 12 bolt. axle ratio could very 2.73 3.08 3.42 3.73 most likey a 3.08
 
If stock should be a rear 12 bolt and a front dana 44

gear ratios varied quite a bit
options are:
2.56 ratio GM8
2.73 ratio GU2
3.08 ratio GU4
3.42 ratio GU6
3.73 ratio GT4

should be able to look in the door hamb or glove box for codes and cross reference/
 
axel ID

The front should be a 10 bolt unless someone changed it. The 77 up had the 10 bolt in it. The rear is a 12 bolt. If the RPO codes are still in the glove box it will have the gear ratio code on it. If you want to pm me I can tell you what the code means. I have a book. Good luck, Brian W.
 
Despite data sheets 77-79 were a mixed bag. Seemed to be whatever Gm had laying around.

My grandfather had an 80 k10 that he bought new and kept through 2000 or so and it had a D44. Ive been argued down that it didnt happen, and I dont have the truck anymore to prove it. But I replaced the front diff cover for him not long before he sold it and it was def a D44....
 
Despite data sheets 77-79 were a mixed bag. Seemed to be whatever Gm had laying around.

My grandfather had an 80 k10 that he bought new and kept through 2000 or so and it had a D44. Ive been argued down that it didnt happen, and I dont have the truck anymore to prove it. But I replaced the front diff cover for him not long before he sold it and it was def a D44....
 
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